SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e23b088e9622338ce0ecf3f341ded3f86613a8f76f0def0131864a7441e19e78' 
  AND token = 'Ejb5OwXmMKNhzoKyJCPEn+5esXSNoxjYTMmBsPSzffk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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