SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b4f1c11b4b70060414b33a237aee146282eb358eddfd2941f17dae5c0abdf0e6' 
  AND token = 'oUPAud9wWQvBz3hZDUEGQ6vw3f5Nt3uXMGHvGUJx+jw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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