SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b5a29e2bdb0156d2b3705f977ce9600c254b80db6ff62a03851f84d267a25478' 
  AND token = 'pF+Z1085Lokk4gwDLVUr5Ka4zoJK93MIgPPjuHmgVKA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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