SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3bf5141b6291f1830f8e66db74226290b605f64e6098d46a4745aec418308e3b' 
  AND token = 'B6LJ1HZpw5mgwpRDoYoK/Taas2rKM+PFZV3HQYvdnO0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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