SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd26339787b5b6549f19607edf81331ac74ae589c50f63c64b47a103398c5214' 
  AND token = 'LjowGOZz+fZI1bfsl+XVWd+VtvT0qzSTsqSuI3+Q6Uc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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