SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b99676badd1739aab926a95d43057f83178e7fc11d10c3e0b4f08a80eaf702f1' 
  AND token = 'WQNrH9dBe9uJTOQGtHADRoZqnBNy+FnGIVLcbmeMl0Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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