SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7f46d312dce02e962187c9764682a298ef1b79b80c2f47a9c251670e81daa6d' 
  AND token = 'nl+81zp1Shn8fkW76hAKp2NqpKD5Ru93J3TdVmjnB08=' 
  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"
    }
  }
}