SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77ea1d3caaeed3016c3ac3079a50fe8426fe4d6e90d610ea8927b6be1fc90241' 
  AND token = 'k0q6jNJwhGsmyk/KNqizUGOzGTpKd95sRTmlcGZtigs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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