SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '629cabda04d3df8a59781aa5a7354445195f279840b09d326b5cfcda9bbb8720' 
  AND token = '4X8PivVowCfR8zWLkVfXRPSlfKoKUQdrdT8fcl6UTgg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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