SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'efdea5a3e1f82c93012297cd922945b6c2eaf474856be6b9940313604ed96db1' 
  AND token = 'EWCaJEPdf/3/QopdMiI1SSnQSQdYYl99SMvN6lfGlT8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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