SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de3a2db8342eea505b0a66a49b57a95a74737cdd3a92894664d824ccae04ef1c' 
  AND token = 'Qb5mWpCKSnM3cyMAc/+kesTCTnTGan+zS5eEkhSoaao=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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