SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '047b8b07188f5efb9f749d7723ee9a8b4e69fc0f6ecd9af903d43d92d4f21771' 
  AND token = 'TRD/ngKw/gIRD+I/przGU4o6u+qqvGIBe4H4hATS5Fc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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