SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0cfa76a5a12543b36ac661e8c02ce2f4d0206829eb956589d3675b17891a0772' 
  AND token = '+zaRqP1bL6UHV9dIlPlMy7OPBrdL4LOuAql8izROsN4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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