SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4fd5e82174e4bf4dc612910843fe53b801773ba4ab04bbe36dad6e947ec42f4' 
  AND token = 'BcG3UlUbcs/kVSJH7giedX7bOC2pe6chZlZFB6gkGZY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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