SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4b5b0195c737b8afe17def089c266db3ebc36f134eaf39c25481afd82019461' 
  AND token = 'no9Bh02bVfU9D5hVcZgv5ALlppLVyJjNWfIk3Po53L0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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