SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '3cf3d2a7366f8f31438cf6f21ab5ffe95570117fa331d99c01eb288d2962b19d' 
  AND token = 'gO2gQ/rN/jqfp0slLrVYHpGXS4/QfFpg3PkmrRB21Nw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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