SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b07b6e51440cb01326fdc71ccc68cd2ecba2430a79875e7f11125e8c1690c62' 
  AND token = 'sLkgBHydmMGmysq5XmwRQAr96O93n/J3peKmLDHee4U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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