SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc360ee2959b03224ce7c62fd830c109445ca5e8aae5f3e8ea13f9b760e2a14b' 
  AND token = 'PQ8V5XWrHGVCb7s5cXuG6B2vrzJWjkZ/K0SFhQE/Qd4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}