SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7ffa1e730406b36e41ac455f3a136adfb1bcdfa29049bd03ba9396b568a50b31' 
  AND token = 'XalCR6WlMbH+yyGrBv+v1SjdQrd+LLVDm4P6xL5femM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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