SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '585778f496d5b13aea117f1a59cf72f9ca6810246b2c001c29db0df639f37d8e' 
  AND token = 'coNKoycrsfiBgcPNkLN/TlSiv8nNFsIvJ/ql8wGSl+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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