SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f51d06bcc754f0511ffefebdee8aef54ada48b32a48c3da817b960c59130faec' 
  AND token = 'ohBdun+vCGLLcNQCd6XNN+Ezu9RXeVABpjXWb9MV3Y0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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