SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c01ff427b327f8bbf66b266cbb886ce8177b09290a364e66b03963d0b5becb5' 
  AND token = 'kZvac/Vtm4OqVU9HNgnx3j3PLVvazbnd1OgXqfGYPX8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00063

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}