SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4477ecf90875d32e4d65350c84435abd21370be065f044937c422ee5069d9d10' 
  AND token = 'FvZ5I2Bfxx4ZV7a0EobgKLVtp6cYCHRST7MDsMBDVN0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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