SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b65881d7fccbae9ee632a0c6e704d41cbf047de94a689e234431d1becc2fbd5' 
  AND token = '4qS0ijm/1pUmG/lx2ylo05nqZ7mzf/Abxm2RB5F3VcI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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