SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e14a530f29d0e58e6554066cd68e2dcfd3b5ff2df4c846297eb37293baf5dbc9' 
  AND token = 'JVA4vuTrXTOGneWmQRN1jkIzxYD+1DHjBTxJMjFzGrk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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