SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85ef2b3c0ed7b79d97f5ef40aabb18cde0ea8327ff668b29d62ac2f6fbb15e78' 
  AND token = 'q2bY3Fngcb3gesxYn2FVxyJZ9R5+vraY6ee0ZhIvINI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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