SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5b736df9535df4ab94c0503c71960cabf995fc88de3a5471e9770108f4e421f' 
  AND token = 'x2RIlOfqZ2fYbdguGyQPZjQ6OOwXI6GLX0m2Zd/BinI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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