SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48cf1903059313860875f6ad7520729b2c2aa48ee14bf71ab29990c7d7044292' 
  AND token = 'gau9ks/kU0y2+iI0le5shXNZ0pjFmlFXjMKAteDeULo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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