SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '934d5e9f1835535f29067f26e4d2b95d054091481f02af715ff1630af9dbfa1e' 
  AND token = 'EFt4YAvP2wLdsiEUwgRvWmrg3B8C99LS9QGXGQbdZOI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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