SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4450a2c27fc86bb5f2cbb915b6c262c58b24a6866af6d42412d5bd3332f0895a' 
  AND token = '9rDJS0F6sMxS9ue2CrWJCw6jdvbQFWzQHkUwNLVpe0M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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