SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f79a8ba6bb776783fe04c31a38fe7b141a6dcbbb31178511e6754014f461e90a' 
  AND token = 'TSUrkMx+aVxym/FuPtcDRy6PcklvdqUVB+f0bjZwI/I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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