SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '988b39b70d89c2150707e054c20ffde13a7c8931cf870bd9031a48891e515aa0' 
  AND token = 'RRfkagsypnINgOcyOao2vqVQmoYcpx/qwTiu1ilrZOs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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