SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e52b0db836142d65b81385511831850a658e3dafb4c44d3f0fb97939fcefddc7' 
  AND token = 'EiakYIgSep99RRniuBb2PGbG7GhsPOzJJLC3cGFcepI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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