SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b1af2368cbb74ccab3802f7ece746a309ce5a1bbcff15d651830bba7c7d0782a' 
  AND token = 'y90dj6C+hZmvNh1jEgWM2oJ2VUOrsBsRgK/O/POf4UM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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