SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ca65ca7916968b080020c4992c765e487842a0b2a987e1abbe1ba82906c19ca' 
  AND token = 'KSBzHl45v3lc5+MtDO+VW1ggqXLOF8eFFNFiebR0TR8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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