SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e95d9eca4f2303d078f13d78004926cdfc53be5c204d99e795d8f6a829b07557' 
  AND token = '/GjyV7zR/useaIuczGoPT98diaeDS7SI+KAcZQYgQQM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}