SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e67d51c8b6d484f65bec85ee53feb57fce31d27b4ca4e83354b0db4ef537059b' 
  AND token = 'oLO2m2RemobxyDqQcptoW4PabQdBQz+GwyIjGUqL4Nc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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