SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23d44dd4ff8fccd5cc4c48891908eeb023aec696a6e0365a143f2627604fcefa' 
  AND token = 'VdKSw0LOaT0ZZelkRUfnEzLaII+d691aDPF5Zn7MxO4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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