SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f228334fac32fefa070eaea60593a998be4b3212a1d3359de7e2d433bb74070a' 
  AND token = 'vs2TC5W1TUR8ASHqn3Pt4DFFjh7o1udqHSHvBLpGDf4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}