SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3024108a887cf44d6efb27fa4ee18b298d3d017beae44116768344fb06c7661e' 
  AND token = 'tZ3nFnaQILs37X6eoGQmIICIxv29NtQPjZm8I/pncEQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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