SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf9107f6635cd3301224f0ec363cbe8399c6fab6b5ab3b6f694ab80892d80376' 
  AND token = 'Uc/aGG8T7KOqDFXhn5+4+d46PewkhChrpLAqkySoK30=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}