SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3c809e106d31ddea4e3638d44c759a985cac4928c9955a236f7cebe6b55aad42' 
  AND token = 'JjtTl19DW66Jt8Xj47GF42uvFmoG8NWl0ukIje2BEmA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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