SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b6d4e9fa9d75480c7dc3191239a261cf459317ffeafe4c274e876d74a5420f7' 
  AND token = 'rQUGffGn1k9U+FQP7Kims4NI/f5hRHSvt4sEgJjAdx0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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