SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38546d65a9b566e468bb250f512aa1cf1afcb88a3737916482423d34af25615b' 
  AND token = 'QNNChqRFDZwhN/pUch7Lf7Teb8YGWUwNU+smtpPGYKY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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