SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '443712dd6931708e6927fbb91756dd4aa886433155d5d24ac98f3c5be4085ca1' 
  AND token = 'SWJTgETfGrmEFvCL4JDdpc8txmc3+94hOVljHjPqMYs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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