SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9993b1cb806c629fac9e2ad4cc7279712c580656dd3c22fe7dc03137d3725ea5' 
  AND token = 'sGWOOMlSN5z9zcKE8Cx7mRpgv/dYySTIpOHrr0d7Jlw=' 
  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"
    }
  }
}