SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6324273de9398f43701a4f412333722c34cfd42992f0d14af4ceef1f79ca353b' 
  AND token = 'BBnC3cxUtkpNhtIRK3R6co2hWSwBCuzcpbRvR3eMfjs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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