SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3439ddf2cadd70dfa49cdd80fc779d1161ccf9c4cbc5153a21034f842ed78d14' 
  AND token = 'g4hikKbzJwS8wxYcuTq3gFLLQypdjftvrjf+jRKpbVU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}