SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0af047ec24ed596a0f03d086cabbac8649b3ed6b1801eac69f2ba8cc70afe9c1' 
  AND token = '5eVk7+mDnyi7fYkM3Fq6YAPsd95DcUwaDHazNHxW8mA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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